The editor of The Philadelphia Inquirer, William K. Marimow, was fired on Monday, according to a brief e-mail sent to staff members by the newspaper’s publisher.

A Pulitzer Prize winner and former investigative journalist, Mr. Marimow was rehired as top editor shortly after the newspaper was bought in April 2012 by a group of local investors who acquired the Philadelphia Media Network, which also publishes The Daily News and Philly.com.